OBJECTIVETo investigate the change in the expression of tight junction protein ZO-1 in intestinal epithelial cells (Caco-2 cells) and the protective effect of eicosapentaenoic acid (EPA) after adherent-invasive Escherichia coli (E.coli) LF82 infection.

METHODSThe Caco-2 cell line was used to establish an in vitro model of tight junction of intestinal epithelial cells. Caco-2 cells were divided into EPA treatment groups (0, 25, 50, 100, and 200 μmol/L EPA) and EPA (0, 25, 50, 100, and 200 μmol/L EPA)+E.coli LF82 treatment (0, 6, and 12 hours) groups. A microscope was used to observe the morphological characteristics of the cells. MTT assay was used to determine the cell growth curve. The activity of alkaline phosphatase (ALP) at both sides of the cell membrane was compared to evaluate the Caco-2 cell model. MTT assay and flow cytometry were used to investigate the effects of different concentrations of EPA on the survival rate and apoptosis rate of Caco-2 cells. RT-qPCR was used to measure the mRNA expression of ZO-1 in Caco-2 cells after EPA and/or E.coli LF82 treatment. ELISA was used to measure the change in the level of tumor necrosis factor-α (TNF-α) in culture supernatant.

RESULTSAfter EPA treatment (25 and 50 μmol/L), the proliferation of Caco-2 cells was induced in a dose-dependent manner. The survival rates of the cells were significantly higher than those in the control group (P<0.05). The EPA treatment (100 and 200 μmol/L) groups had a significant inhibitory effect on the proliferation of Caco-2 cells in a dose-dependent manner. The survival rates of the cells were significantly lower than those in the control group (P<0.05). The EPA treatment (100 and 200 μmol/L) groups had a significant increase in cell apoptosis rate compared with the control group (P<0.05). The 6- and 12-hour E.coli LF82 treatment groups had decreasing mRNA expression of ZO-1 in Caco-2 cells over the time of treatment and had significantly lower mRNA expression of ZO-1 than the untreated group (P<0.05). The Caco-2 cells treated with E.coli LF82 and 25 or 50 μmol/L EPA for 6 or 12 hours showed an increase in the mRNA expression of ZO-1 with the increasing concentration of EPA, as well as significantly higher mRNA expression of ZO-1 than the Caco-2 cells treated with E.coli LF82 alone (P<0.05). The Caco-2 cells treated with E.coli LF82 alone for 6 or 12 hours had increasing secretion of TNF-&alpha; over the time of treatment and had significantly higher secretion than the untreated Caco-2 cells (P<0.05). The Caco-2 cells treated with E.coli LF82 and 25 or 50 μmol/L EPA for 6 or 12 hours showed a reduction in the secretion of TNF-&alpha; with the increasing concentration of EPA and had significantly lower secretion than the Caco-2 cells treated with E.coli LF82 alone (P<0.05).

CONCLUSIONSEPA can effectively prevent the destruction of tight junction of intestinal epithelial cells induced by E.coli LF82 infection and inhibit the secretion of inflammatory factors. Therefore, it has a certain protective effect on intestinal mucosal barrier.

Apoptosis ; drug effects ; Caco-2 Cells ; Eicosapentaenoic Acid ; pharmacology ; Escherichia coli ; pathogenicity ; Humans ; Intestinal Mucosa ; metabolism ; microbiology ; RNA, Messenger ; analysis ; Tight Junctions ; drug effects ; Tumor Necrosis Factor-alpha ; secretion ; Zonula Occludens-1 Protein ; genetics

OBJECTIVETo explore the role of HIV-1 tat gene variations in AIDS dementia complex (ADC) pathogenesis.

METHODSHIV-1 tat genes derived from peripheral spleen and central basal ganglia of an AIDS patient with ADC and an AIDS patient without ADC were cloned for sequence analysis. HIV-1 tat gene sequence alignment was performed by using CLUSTAL W and the phylogentic analysis was conducted by using Neighbor-joining with MEGA4 software. All tat genes were used to construct recombinant retroviral expressing vector MSCV-IRES-GFP/tat. The MSCV-IRES-GFP/tat was cotransfected into 293T cells with pCMV-VSV-G and pUMVC vectors to assemble the recombinant retrovirus. After infection of gliomas U87 cells with equal amount of the recombinant retrovirus, TNF-&alpha;, and IL-1β concentrations in the supernatant of U87 cells were determined with ELISA.

RESULTSHIV-1 tat genes derived from peripheral spleen and central basal ganglia of the AIDS patient with ADC and the other one without ADC exhibited genetic variations. Tat variations and amino acid mutation sites existed mainly at Tat protein core functional area (38-47aa). All Tat proteins could induce U87 cells to produce TNF-&alpha; and IL-1β, but the level of IL-1β production was different among Tat proteins derived from the ADC patient's spleen, basal ganglia, and the non-ADC patient's spleen. The level of Tat proteins derived from the ADC patient's spleen, basal ganglia, and the non-ADC patient's spleen were obviously higher than that from the non-ADC patient's basal ganglia.

CONCLUSIONTat protein core functional area (38-47aa) may serve as the key area of enhancing the secretion of IL-1β. This may be related with the neurotoxicity of HIV-1 Tat.

AIDS Dementia Complex ; metabolism ; pathology ; virology ; Adult ; Amino Acid Sequence ; Basal Ganglia ; virology ; Cell Line, Tumor ; Gene Expression Regulation, Viral ; Genes, tat ; HIV-1 ; genetics ; pathogenicity ; Humans ; Interleukin-1beta ; biosynthesis ; genetics ; secretion ; Middle Aged ; Molecular Sequence Data ; Neuroglia ; pathology ; secretion ; Spleen ; virology ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics ; secretion ; tat Gene Products, Human Immunodeficiency Virus ; genetics ; physiology

As a superantigen protein, Staphylococcal enterotoxin C2 (SEC2) activates the immune system effectively even in extremely low concentrations, and this property could be applied in adjuvant therapy against tumors and infectious diseases. In order to enhance the superantigen activity of SEC2, the residues at position 102-106 of native SEC2 were substituted for WWH, WWT and WWP by over-lap PCR, and three mutants named ST-1, ST-2 and ST-3 were obtained. Stimulating activity to murine lymphocytes proliferation and inhibiting activity to tumor cell growth of the three mutants were significantly improved compared with the native SEC2. Febrile activities of ST-1 and ST-3 were comparable with the native SEC2, but ST-2 showed markedly increased febrile activity than native SEC2. Moreover, the levels of IL-2, IFN-gamma and TNF-alpha secreted by T cells stimulated with the three mutants were significantly improved, which might be the possible reason for enhanced tumor cell growth inhibition activities. Furthermore, mVbeta8.2 gene transcription levels of murine splenocytes stimulated by the three mutants were dramatically increased compared with native SEC2, suggesting their increased affinities to TCR mVbeta8.2 molecular, which might be the main reason for their enhanced superantigen activities.
Animals ; Enterotoxins ; genetics ; immunology ; Female ; Interferon-gamma ; secretion ; Interleukin-2 ; secretion ; Lymphocyte Activation ; Mice ; Mice, Inbred BALB C ; Mutant Proteins ; genetics ; immunology ; Receptors, Antigen, T-Cell ; immunology ; Superantigens ; genetics ; immunology ; Tumor Necrosis Factor-alpha ; secretion

OBJECTIVETo study whether the protective effects of glutamine against intestinal injury are associated with the regulation of intestinal secretion of NF-κB and TNF-&alpha; by glutamine.

METHODSTwenty-four 10-day-old Wistar rat pups were randomly intraperitoneally injected with normal sodium of 1 mL/kg (control group; n=8), LPS of 5 mg/kg (endotoxemia group; n=8) or LPS of 5 mg/kg plus glutamine of 10 mL/kg (glutamine group; n=8). The rats were sacrificed 3 hrs after injection. A segment of distal ileum was dissected. The pathologic changes of the small intestine were observed under an optical microscope (hematoxylin-eosin staining). The expression of intestinal NF-κB mRNA and protein were detected by RT-PCR and Western blot respectively. The TNF-&alpha; level in intestinal tissues was measured using ELISA.

RESULTSThe structure of the small intestine in the control group remained normal. The inflammation cells infiltration and the edema of interstitial substance and epithelials were observed in the endotoxemia and glutamine groups. The pathologic changes in the glutamine group were significantly alleviated when compared with the endotoxemia group. The expression of NF-κB mRNA and protein in the glutamine group was significantly lower than that in the endotoxemia group (P<0.01). The secretion of TNF-&alpha; in the glutamine group was significantly lower than that in the endotoxemia group (P<0.01).

CONCLUSIONSThe protective effects of glutamine against intestinal injury may be associated with the down-regulation of intestinal NF-κB mRNA and protein expression and the reduction of the secretion of TNF-&alpha;.

Animals ; Endotoxemia ; metabolism ; Female ; Glutamine ; pharmacology ; Intestines ; drug effects ; metabolism ; Male ; NF-kappa B ; analysis ; genetics ; secretion ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; secretion

OBJECTIVETo investigate the effect of ADMA on macrophage migration inhibitory factor (MIF) expression and tumor necrosis factor-&alpha; (TNF-&alpha;) and IL-8 secretion in THP-1 monocyte-derived macrophages. METHIDS: THP-1 monocytes were induced to differentiate into macrophages by a 24-h incubation with 160 nmol/L PMA. The THP-1 monocyte-derived macrophages were exposed to different concentrations of ADMA for 24 h, and the changes in MIF mRNA and protein expressions were analyzed with RT-PCR and Western blotting, respectively. Enzyme-linked immunosorbent assay was used to detect the levels of TNF-&alpha; and IL-8 in the supernatant of THP-1-derived macrophages following ADMA treatments.

RESULTSADMA obviously up-regulated MIF mRNA and protein expressions in THP-1-derived macrophages in a concentration- dependent manner. Exposure of the cells to 15 µmol/L ADMA for 24 h showed the most potent effect in up-regulating MIF mRNA and protein expressions. ADMA treatment also resulted in a dose-dependent increase of the levels of TNF-&alpha; and IL-8 in the culture supernatant of the macrophages, and the peak levels occurred following the treatment with 15 µmol/L ADMA.

CONCLUSIONADMA can up-regulate MIF expression and induce TNF-&alpha; and IL-8 secretion in THP-1 monocyte-derived macrophages.

Arginine ; analogs & derivatives ; pharmacology ; Cell Differentiation ; Cell Line ; Humans ; Interleukin-8 ; secretion ; Intramolecular Oxidoreductases ; genetics ; metabolism ; Macrophage Migration-Inhibitory Factors ; genetics ; metabolism ; Macrophages ; cytology ; metabolism ; Monocytes ; cytology ; Phenanthrenes ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; secretion

BACKGROUNDTissue-engineered bioartificial muscle-based gene therapy represents a promising approach for the treatment of heart diseases. Experimental and clinical studies suggest that systemic administration of insulin-like growth factor-1 (IGF-1) protein or overexpression of IGF-1 in the heart exerts a favorable effect on cardiovascular function. This study aimed to investigate a chronic stage after myocardial infarction (MI) and the potential therapeutic effects of delivering a human IGF-1 gene by tissue-engineered bioartificial muscles (BAMs) following coronary artery ligation in Sprague-Dawley rats.

METHODSLigation of the left coronary artery or sham operation was performed. Primary skeletal myoblasts were retrovirally transduced to synthesize and secrete recombinant human insulin-like growth factor-1 (rhIGF-1), and green fluorescent protein (GFP), and tissue-engineered into implantable BAMs. The rats that underwent ligation were randomly assigned to 2 groups: MI-IGF group (n = 6) and MI-GFP group (n = 6). The MI-IGF group received rhIGF-secreting BAM (IGF-BAMs) transplantation, and the MI-GFP group received GFP-secreting BAM (GFP-BAMs) transplantation. Another group of rats served as the sham operation group, which was also randomly assigned to 2 subgroups: S-IGF group (n = 6) and S-GFP group (n = 6). The S-IGF group underwent IGF-1-BAM transplantation, and S-GFP group underwent GFP-BAM transplantation. IGF-1-BAMs and GFP-BAMs were implanted subcutaneously into syngeneic rats after two weeks of operation was performed. Four weeks after the treatment, hemodynamics was performed. IGF-1 was measured by radioimmunoassay, and then the rats were sacrificed and ventricular samples were subjected to immunohistochemistry. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to examine the mRNA expression of bax and Bcl-2. TNF-&alpha; and caspase 3 expression in myocardium was examined by Western blotting.

RESULTSPrimary rat myoblasts were retrovirally transduced to secrete rhIGF-1 and tissue-engineered into implantable BAMs containing parallel arrays of postmitotic myofibers. In vitro, they secreted consistent levels of hIGF (0.4 - 1.2 µg×BAM(-1)×d(-1)). When implanted into syngeneic rat, IGF-BAMs secreted and delivered rhIGF. Four weeks after therapy, the hemodynamics was improved significantly in MI rats treated with IGF-BAMs compared with those treated with GFP-BAMs. The levels of serum IGF-1 were increased significantly in both MI and sham rats treated with IGF-BAM. The mRNA expression of bax was lower and Bcl-2 expression was higher in MI-IGF group than MI-GFP group (P < 0.05). Western blotting assay showed TNF-&alpha; and caspase 3 expression was lower in MI-IGF group than MI-GFP group after therapy.

CONCLUSIONSrhIGF-1 significantly improves left ventricular function and suppresses cardiomyocyte apoptosis in rats with chronic heart failure. Genetically modified tissue-engineered BAMs provide a method delivering recombinant protein for the treatment of heart failure.

Animals ; Apoptosis ; Caspase 3 ; analysis ; Desmin ; analysis ; Genetic Therapy ; Heart Failure ; pathology ; physiopathology ; therapy ; Insulin-Like Growth Factor I ; genetics ; secretion ; Myoblasts, Skeletal ; metabolism ; Myocytes, Cardiac ; pathology ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; secretion ; Retroviridae ; genetics ; Tissue Engineering ; Tumor Necrosis Factor-alpha ; analysis ; Ventricular Function, Left

This investigation was made in regard to the changes of plasma Leptin, Tumor Necrosis Factor-alpha (TNF-alpha) and Neuropeptide Y (NPY) levels and their association with insulin resistance and beta-cell secretion function in normal glucose tolerant first-degree relatives of familial type 2 diabetic pedigrees in Chengdu area. Levels of Leptin, TNF-alpha, NPY and lipids (TG, TC, HDL-C) were determined in 86 type 2 diabetic mellitus (DM) patients, 73 normal glucose tolerant (NGT) first-degree relatives in familial type 2 diabetic pedigrees and 65 normal controls (NC) from non-diabetic families. All of the subjects underwent 75 g oral glucose tolerance test (OGTT). Plasma glucose, immunoreactive insulin (IRI) and true insulin (TI) levels were also determined. Fasting glucose and TI levels were used to calculate homeostasis model assessment-insulin resistance (HOMA-IR) and HOMA-beta cell indexes. After being adjusted for age and body mass index (BMI), the levels of Leptin in DM and NGT first-degree relatives were all significantly higher than that in normal controls (P < 0.05). Type 2 diabetic patients showed significantly elevated TNF-alpha levels than did the normal controls (P < 0.05). Furthermore, diabetic subjects showed significantly higher HOMA-IR and lower HOMA-B levels, compared with those in NGT and NC groups (P < 0.05). No statistically significant difference was found in regard to NPY among three groups. NGT first-degree relatives showed significantly higher levels of TG, fasting IRI, OGTT-2h IRI and HOMA-IR than did the normal controls (P < 0.05). Leptin was positively correlated with age, BMI, waist, A1c, fasting and OGTT-2h glucose, OGTT-2h TI and TNF-alpha in all subjects, and was negatively correlated with HOMA-B in females. Leptin levels were significantly elevated in NGT first-degree relatives, which implied that genetic defects of Leptin may play a role in the development of familial type 2 diabetic pedigrees.
Adult ; Case-Control Studies ; Diabetes Mellitus, Type 2 ; blood ; genetics ; Female ; Glucose Tolerance Test ; Humans ; Insulin ; secretion ; Insulin Resistance ; Leptin ; blood ; Male ; Middle Aged ; Neuropeptide Y ; blood ; Pedigree ; Tumor Necrosis Factor-alpha ; blood

OBJECTIVETo study the experimental efficacy of Qushi Huayu Decoction (祛湿化瘀方,QHD) on, protein and gene expression of cathepsin B (ctsb) in HepG2 cells induced by free fatty acids (FFAs).

METHODSThe model of HepG2 steatosis and tumor necrosis factor-&alpha; (TNF-&alpha;) secretion was induced by long-chain FFAs. HepG2 cells were divided into 4 groups: control group (group C), model group (group M), low-dose QHD group (group L) and high-dose QHD group (group H). Long-chain FFAs were added to groups M, L and H. The 10% blank-control serum was added to group C and M, while 5% and 10% QHD-containing sera were added to group L and H, respectively. The levels of serum TNF-&alpha; and cellular triglyceride (TG) were detected. Cellular p-IκB and ctsb expression were detected using Western blot and PCR. The expression and distribution of ctsb were observed by immunofluorescence.

RESULTSAfter incubating with FFA for 24 h, TG deposition in HepG2, TNF-&alpha; content in cell supernatant, the protein expression of cellular ctsb and P-IκB, as well as mRNA expression of ctsb increased markedly in group M compared with group C (P<0.05, P<0.01). Compared with group M, TG deposition, the expression of cellular ctsb, P-IκB and ctsb mRNA in groups L and H, as well as TNF-&alpha; content in group H, decreased significantly (P<0.05). Cell immunochemical fluorescence studies showed that ctsb was released from lysosomes and distributed in the cytoplasm extensively and diffusedly after being stimulated with FFA. In this study, these above-mentioned changes were inhibited markedly in groups L and H.

CONCLUSIONQHD might have a direct inhibitory effect on the ctsb target in the FFA-ctsb-TNF&alpha; pathway of hepatic lipotoxicity.

Cathepsin B ; genetics ; metabolism ; Cell Death ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Fatty Acids ; pharmacology ; Gene Expression Regulation, Enzymologic ; drug effects ; Hep G2 Cells ; Humans ; I-kappa B Proteins ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; NF-KappaB Inhibitor alpha ; RNA, Messenger ; genetics ; metabolism ; Subcellular Fractions ; drug effects ; enzymology ; Triglycerides ; metabolism ; Tumor Necrosis Factor-alpha ; secretion

OBJECTIVETo evaluate the effect of Jianpi Huoxue decoction (JHD)-containing serum on tumor necrosis factor-alpha (TNF-alpha) secretion and endotoxin receptor gene expression in RAW264.7 cells induced by lipopolysaccharide (LPS).

METHODSThe cytotoxicity of blank-control serum and JHD-containing serum at different concentrations were evaluated through the lactate dehydrogenase (LDH) assay in RAW264.7 cells. RAW264.7 cells were divided into six groups: 5% blank-control serum group (C1, n=3), 5% blank-control serum plus LPS group (L1, n=4), 5% JHD-containing serum plus LPS group (J1, n=4), 10% blank-control serum group (C2, n=3), 10% blank-control serum plus LPS group (L2, n=4), and 10% JHD-containing serum plus LPS group (J2, n=4). After cultured with the corresponding serum for 1 h, cells in L1, L2, J1 and J2 were treated with LPS (0.1 microg/mL) for 12 h without rinse. The supernate, cells, protein and RNA were collected for assay. TNF-alpha in the culture supernate was assayed by the enzyme linked immunosorbent assay (ELISA). Protein expression of TNF-alpha in RAW cells was detected by Western-blot. TNF-alpha, Toll-like receptor 2 (TLR2), TLR4 and CD14 mRNA expression in RAW cells were detected by real-time RT-PCR.

RESULTSThe LDH assay supported that cultured for 24 h or less with the JHD-containing serum at the concentration of 10% or lower, RAW264.7 cells showed no cytotoxicity. After stimulation with LPS for 2 h, TNF-alpha in the culture supernate of the 5% blank-control serum plus LPS group (L1, P=0.03), 10% blank-control serum plus LPS group (L2, P=0.002) and in the cell layer (P=0.01) of these groups increased remarkably. After stimulation with LPS for 1 h, the mRNA expression of TNF-alpha (P=0.004), TLR (P=0.03), CD14 (P=0.004) was up-regulated obviously. In the 10% JHD-containing serum plus LPS group (J2), the protein expression of TNF-alpha in both supernate (P=0.04) and cell layer (P=0.04), gene expression of TNF-alpha (P=0.03), TLR4 (P=0.001), CD14 (P=0.001) were all inhibited. On the other hand, the TLR2 mRNA expression was not up-regulated after LPS stimulation in the 10% blank-control serum plus LPS group (L2).

CONCLUSIONJHD-containing serum inhibited the LPS-induced cytokines expression in RAW264.7 which was probably associated with its inhibitory effect on the mRNA expression of LPS receptors TLR and CD14.

Animals ; Cell Line ; Culture Media ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression ; drug effects ; Lipopolysaccharide Receptors ; genetics ; Lipopolysaccharides ; pharmacology ; Macrophages ; cytology ; drug effects ; metabolism ; Male ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Immunologic ; genetics ; Serum ; Signal Transduction ; drug effects ; Toll-Like Receptor 2 ; genetics ; Toll-Like Receptor 4 ; genetics ; Tumor Necrosis Factor-alpha ; metabolism ; secretion

OBJECTIVETo study the effect of a new obesity-related gene NYGGF4 on the insulin sensitivity and secretory function of adipocytes.

METHODS3T3-L1 preadipocytes transfected with either an empty expression vector (pcDNA3.1; control group) or an NYGGF4 expression vector (NYGGF4-pcDNA3.1) were cultured in vitro and differentiated into the matured adipocytes with the standard insulin plus dexamethasone plus 3-isobutyl-methylxanthine (MDI) induction cocktail. 2-deoxy-D-[3H] glucose uptake was determined by liquid scintillation counting. Western blot was performed to detect the protein content and translocation of glucose transporter 4 (GLUT4). The supernatant concentrations of TNF-alpha, IL-6, adiponectin and resistin were measured using ELISA.

RESULTSNYGGF4 over-expression in 3T3-L1 adipocytes reduced insulin-stimulated glucose uptake. NYGGF4 over-expression impaired insulin-stimulated GLUT4 translocation without affecting the total protein content of GLUT4. The concentrations of TNF-alpha, IL-6, adiponectin and resistin in the culture medium of 3T3-L1 transfected with NYGGF4 were not significantly different from those in the control group.

CONCLUSIONSNYGGF4 over-expression impairs the insulin sensitivity of 3T3-L1 adipocytes through decreasing GLUT4 translocation and had no effects on the secretory function of adipocytes.

3T3-L1 Cells ; Adipocytes ; drug effects ; secretion ; Adiponectin ; secretion ; Animals ; Carrier Proteins ; genetics ; physiology ; Glucose ; metabolism ; Glucose Transporter Type 4 ; analysis ; metabolism ; Insulin ; pharmacology ; Interleukin-6 ; secretion ; Mice ; Resistin ; analysis ; Transfection ; Tumor Necrosis Factor-alpha ; secretion